fantasy world where every single person is born with one thing they're THE absolute best at by a huge and insurmountable margin, which they can do flawlessly without the need for any sort of practice or preparation. we'll call it their Talent with a neat lil' capital T.
since there's lots of people in the world though everybody's Talent has to be pretty specific to still make sure everybody gets one individual gift. so your Talent wouldn't be just baking it would have to be baking fruit pies or maybe even just strawberry pies, where even if you haven't baked another thing in your life before people would cry tears of joy from how delicious your strawberry pies are, but so help you if you try that shit with peaches.
the other bittersweet is that Talent is completely random and doesn't cater to your likes or dislikes or any other preferences at all. hate dogs? scared of dogs? allergic to dogs? all of the above? too bad, you're still the world's best dog groomer. is your name bob mc cisheterson? well damn, title of world's best sucker of dicks sure is wasted on you.
finally there's something that could go either way and it'll influence how this fantasy world develops over the years/decades/centuries. if somebody who has a Talent dies it could either make their Talent up for grabs again, or it means their Talent dies with them.
other things to consider: are people drawn to their Talent or do they have no clue, like will people have a sense of what they're amazing at or is there just a huge portion of the population that never discovers their Talent because it happens to be something they didn't try? next question, does Talent draw from all points of time in the past present future or not? is there a world's best linotype operator born in 2022? is some 16th Century peasant doomed to never know about his Talent in playing tetris?